MOCVD of SrTa2O6 Thin Films for High-k Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
Stephan Regnery ◽  
Reji Thomas ◽  
Hans Haselier ◽  
Peter Ehrhart ◽  
Rainer Waser ◽  
...  
Keyword(s):  
Thin Films ◽  
Process Window ◽  
Leakage Currents ◽  
Si Substrates ◽  
Mocvd Reactor ◽  
Low Leakage ◽  
High K ◽  
Single Source Precursor ◽  
Mis Capacitors ◽  
Low Pressures

ABSTRACTSrTa2O6 thin films with thickness between 6 and 150nm were deposited in a multi-wafer planetary MOCVD reactor combined with a TRIJET® liquid delivery system using a single source precursor, strontium-tantalum-(methoxyethoxy)-ethoxide dissolved in toluene. A rather narrow process window for the deposition of stoichiometric SrTa2O6 was found for this precursor at low pressures and a susceptor temperature around 500°C. Films were grown on Pt/TiO2/SiO2/Si, TiNx/Si, and SiO2/Si substrates. The as-deposited films were X-ray amorphous and could be crystallized by post-annealing at a temperature ≥700°C. The SrTa2O6 phase was dominating within a broad range of compositions (Sr/Ta: 0.4–0.7) and a perovskite type phase was observed for Sr/Ta > 0.7. The electrical properties have been investigated with MIM and MIS capacitors after sputter deposition of Pt top electrodes. The amorphous films had a relative permittivity, ε, in the range of 25–45, and low leakage currents. Crystallized films were investigated with Pt MIM capacitors. For stoichiometric SrTa2O6 the dielectric permittivity reached values of ε = 100–110, but the leakage currents were increased. Remarkably, the permittivity is not very sensitive to deviations from the exact stoichiometry of the SrTa2O6 phase (Sr/Ta: 0.40.7), but a decrease to values of ε = 30–40 is observed along with the phase transition at high Sr contents.

Relaxation Behavior and Breakdown Mechanisms of Nanocrystals Embedded Zr-doped HfO2 High-k Thin Films for Nonvolatile Memories

2008 ◽  
Vol 1071 ◽  
Author(s):  
Chia-Han Yang ◽  
Yue Kuo ◽  
Chen-Han Lin ◽  
Rui Wan ◽  
Way Kuo
Keyword(s):  
Nonvolatile Memory ◽  
Storage Capacity ◽  
Breakdown Strength ◽  
Charge Storage ◽  
Leakage Currents ◽  
Low Leakage ◽  
Nonvolatile Memories ◽  
High K ◽  
Memory Characteristics ◽  
Large Charge

AbstractSemiconducting or metallic nanocrystals embedded high-k films have been investigated. They showed promising nonvolatile memory characteristics, such as low leakage currents, large charge storage capacities, and long retention times. Reliability of four different kinds of nanocrystals, i.e., nc- Ru, -ITO, -Si and -ZnO, embedded Zr-doped HfO2 high-k dielectrics have been studied. All of them have higher relaxation currents than the non-embedded high-k film has. The decay rate of the relaxation current is in the order of nc-ZnO > nc-ITO > nc-Si > nc-Ru. When the relaxation currents of the nanocrystals embedded samples were fitted to the Curie-von Schweidler law, the n values were between 0.54 and 0.77, which are much lower than that of the non embedded high-k sample. The nanocrystals retain charges in two different states, i.e., deeply and loosely trapped. The ratio of these two types of charges was estimated. The charge storage capacity and holding strength are strongly influenced by the type of material of the embedded nanocrystals. The nc-ZnO embedded film holds trapped charges longer than other embedded films do. The ramp-relax result indicates that the breakdown of the embedded film came from the breakdown of the bulk high-k film. The type of nanocrystal material influences the breakdown strength.

The Influence of Annealing Temperature on the Characteristics of 0.95 (Na0.5Bi0.5)TiO3-0.05 BaTiO3 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 263-266
Author(s):  
Chien Chen Diao ◽  
Chia Ching Wu ◽  
Cheng Fu Yang ◽  
Chao Chin Chan
Keyword(s):  
Thin Films ◽  
Deposition Process ◽  
Leakage Currents ◽  
Cross Sectional ◽  
Si Substrates ◽  
Polarization Characteristics ◽  
Magnetron Sputter ◽  
Xrd Patterns ◽  
Top View ◽  
Better Than

In this study, 0.95 (Na0.5Bi0.5)TiO3-0.05 BaTiO3 + 1 wt% Bi2O3 (NBT-BT3) composition sintered at 1200oC for 2h is used as target to deposit the NBT-BT3 thin films. The excess 1wt% Bi2O3 is used to compensate the vaporization of Bi2O3 during the deposition process. Ferroelectric NBT-BT3 thin films are deposited on SiO2/Si and Pt/Ti/SiO2/Si substrates using RF magnetron sputter method using the ceramic target fabricated by ourselves. After depositing under the optimal parameters, the thin films are then heated by a conventional thermal annealing (CFA) process conducted in air at temperatures ranging from 600- 800oC for 60min. The morphologies of NBT- BT3 thin films are observed using SEM the crystalline structures of NBT-BT3 thin films are investigated using XRD patterns. The large memory window and stable leakage current density examination reveals that NBT-BT3 thin films annealed on 600oC are better than other thin films under different CTA temperatures. Finally, the top view and cross-sectional images of SEM, memory windows, leakage currents and polarization characteristics of NBT-BT3 thin films are also well developed.

scholarly journals Dielectric tunable characteristics of compositional-gradient BaTi1−xSnxO3 thin films

2021 ◽  
Vol 11 (04) ◽  
pp. 2150019
Author(s):  
Chenjing Wu ◽  
Manwen Yao
Keyword(s):  
Thin Films ◽  
Impedance Matching ◽  
Sol Gel ◽  
Temperature Stability ◽  
Dielectric Behavior ◽  
Compositional Gradient ◽  
Dielectric Tunability ◽  
Temperature Range ◽  
Si Substrates ◽  
Low Leakage

Compositional-gradient [Formula: see text][Formula: see text]O3 thin films on Pt(100)/Ti/SiO2/Si substrates are fabricated with sol–gel using spin coating. All of the structures of the prepared thin films are of single-phase crystalline perovskite with a dense and crack-free surface morphology. BTS10/15/20 thin film exhibits enhanced temperature stability in its dielectric behavior. The temperature coefficient of capacitance [Formula: see text] in the temperature range from [Formula: see text]C to [Formula: see text]C is [Formula: see text]C and that of [Formula: see text] in the temperature range from [Formula: see text]C to [Formula: see text]C is [Formula: see text]C. Furthermore, the thin films show low leakage current density and dielectric loss. High and stable dielectric tunable performances are found in BTS10/15/20 thin films: the dielectric tunability of the thin films is around 20.1% under a bias voltage of 8 V at 1 MHz and the corresponding dielectric constant is in the range between 89 and 111, which is beneficial for impedance matching in circuits. Dielectric tunability can be obtained under a low tuning voltage, which helps ensure safety. The simulated resonant frequency of the compositional-gradient BTS thin films depends on the bias electric field, showing compositional-gradient BTS thin films could be used in electrically tunable components and devices. These properties make compositional-gradient BTS thin films a promising candidate for dielectric tuning.

Dielectric and Ferroelectric studies of Pb0.85La0.15TiO3 Thin Films on solution derived RuO2 Bottom Electrodes

2001 ◽  
Vol 672 ◽  
Author(s):  
S. Bhaskar ◽  
S. B. Majumder ◽  
P. S. Dobal ◽  
S. B. Krupanidhi ◽  
R. S. Katiyar
Keyword(s):  
Thin Films ◽  
Profile Analysis ◽  
Sol Gel ◽  
Dielectric Behavior ◽  
Tangent Loss ◽  
Film Electrode ◽  
Secondary Phases ◽  
Leakage Currents ◽  
Low Leakage ◽  
Electrode Interface

ABSTRACTSol-Gel derived Pb0.85La0.15TiO3 PLT15) thin films were deposited on solution derived RuO2/Si, RuO2/Pt/Si and Pt bottom electrodes. Dielectric, tangent loss, hysteresis, J-E, measurements were also carried out on these films. X-ray results established the single phase perovskite formation with no secondary phases of PLT15 thin film on these electrodes. PLT15 thin films on RuO2 bottom electrode showed relatively inferior ferroelectric and dielectric behavior as compared to Pt electrode. Low leakage currents (10-8 A/cm2 at 10 kV/cm) and the observed J-E characteristics have been attributed to poor film-electrode interface. Observed electrical and dielectric properties have been correlated with the film-electrode interface. The interface characteristics were further augmented by depth profile analysis using Auger Electron Spectroscopy.

Gate-All-Around (GAA) Fully Depleted (FD) Cantilever Channel MOSFET with High-k Dielectric and Metal Gate

2007 ◽  
Vol 995 ◽  
Author(s):  
Sagnik Dey ◽  
Se-Hoon Lee ◽  
Sachin V. Joshi ◽  
Prashant Majhi ◽  
Sanjay K. Banerjee
Keyword(s):  
Metal Gate ◽  
Leakage Currents ◽  
Drive Current ◽  
Fully Depleted ◽  
Low Leakage ◽  
High Drive ◽  
High K ◽  
High K Dielectric

AbstractA MOSFET formed by a Si cantilever channel suspended between source/drain “anchors” wrapped all-around by high-κ dielectric and metal gate is demonstrated. The device shows excellent subthreshold characteristics and low leakage currents due to the fully depleted body and the gate-all-around architecture implemented with a high-κ dielectric and metal gate. At the same time this also allows a high drive current due to mobility enhancements arising from volume inversion of the cantilever channel such that a large ION/IOFF is achieved.

MICROSTRUCTURE AND PROPERTIES OF Sm-DOPED BaTiO3 SPUTTERED FILMS: EFFECTS OF POST-ANNEALINGS AND DOPANT CONTENT

2011 ◽  
Vol 25 (11) ◽  
pp. 1559-1565
Author(s):  
C. H. WU ◽  
J. P. CHU ◽  
S. F. WANG ◽  
W. Z. CHANG
Keyword(s):  
Thin Films ◽  
Rf Magnetron Sputtering ◽  
Dopant Content ◽  
Si Substrates ◽  
Sputtered Films ◽  
Annealing Temperatures ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Electrical Characterizations ◽  
Sputtering System

Sm-doped BaTiO 3 thin films with ~200 nm thickness fabricated by rf magnetron sputtering system onto Pt/Ti/SiO 2/ Si substrates have been investigated. The effects of postannealing and the dopant content in a range of 0.1 to 2.2 at.% on microstructure and electrical properties were studied. The films were found to be amorphous in the as-deposited state and became fully crystallized after annealing at 750°C and above. The addition of Sm in the BaTiO 3 films resulted in the inhibition of grain growth. Electrical characterizations show that the dielectric permittivity increased with increasing annealing temperatures and the 2.2% Sm-doped film had the low leakage current of 1.29×10-9 A at an applied electric field of 100 KV/cm.

Structural and Electrical Properties of BaTio3 Thin Films Grown on p-Si Substrates with Different Device Designs

1993 ◽  
Vol 318 ◽  
Author(s):  
L. H. Chang ◽  
Q. X. Jia ◽  
W. A. Anderson
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Single Layer ◽  
Relative Dielectric Constant ◽  
Rf Magnetron Sputtering ◽  
Phonon Modes ◽  
Si Substrates ◽  
Low Leakage ◽  
Low Leakage Current

ABSTRACTRF magnetron sputtering of BaTiO3 on (100) p-Si was performed to produce a high-quality BaTiO3/p-Si interface and BaTi03 insulator gates with high dielectric constant and low leakage current. Through different processing and device designs, different capacitor structures, including single layer amorphous, single layer polycrystalline and bi-layer amorphous on polycrystal-line, were investigated in this study. Raman spectroscopy showed the optical phonon modes of the BaTiO3 thin films with different structures. The structural properties of the films were characterized by X-ray diffraction. Using both the quasistatic and the high-frequency capacitance-voltage measurements, the interface-trap density was estimated at high 1011 eV−1 cm−2. The relative dielectric constant of the composite structure was controlled in a range from 30 to 130. The leakage current density was as low as 8×10−10 A/cm2 at a field intensity of (2±0.5)×105 V/cm. Breakdown voltage varied from 5x105 to 2×106 V/cm.

Silicon-On-Insulator Mosfets Fabricated in Zone-Melting-Recrystallized Poly-Si Films on SiO2

1981 ◽  
Vol 4 ◽  
Author(s):  
B­Y. Tsaur ◽  
M. W. Gels ◽  
John C. C. Fan ◽  
D. J. Silversmith ◽  
R. W. Mountain
Keyword(s):  
Carrier Mobility ◽  
High Surface ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Surface Electron ◽  
Leakage Currents ◽  
Si Substrates ◽  
Enhancement Mode ◽  
Low Leakage ◽  
Si Films

ABSTRACTN- and p-channel enhancement-mode MOSFETs have been fabricated in Si films prepared by zone-melting recrystallization of poly-Si deposited on SiO2-coated Si substrates. The transistors exhibit high surface mobilities, in the range of 560–620 cm2/V−s for electrons and 200–240 cm2/V−s for holes, and low leakage currents of the order of 0.1 pA/μm (channel width). Uniform device performance with a yield exceeding 90% has been measured in tests of more than 100 devices. The interface between the Si film and the SiO2 layer on the substrate is characterized by an oxide charge density of 1–2 × 1011 cm−2 and a high surface carrier mobility. N-channel MOSFETs fabricated inSi films recrystallized on SiO2-coated fused quartz subtrates exhibit surface electron mobilities substantially higher than those of single-crystal Si devices because the films are under a large tensile stress.

Thin Na0.5K0.5NbO3 Films for Varactor Applications

2000 ◽  
Vol 623 ◽  
Author(s):  
C.-R. Cho ◽  
J.-H. Koh ◽  
A. Grishin ◽  
S. Abadei ◽  
P. Petrov ◽  
...  
Keyword(s):  
Microwave Frequency ◽  
Dissipation Factor ◽  
Leakage Currents ◽  
Low Frequencies ◽  
Si Substrates ◽  
Low Dielectric ◽  
Low Leakage ◽  
Tunable Microwave Device ◽  
Device Applications ◽  
Spectroscopy Studies

AbstractSingle phase Na0.5K0.5NbO3 (NKN) thin films have been pulsed laser deposited on SiO2/Si(C-01) wafers and LaAlO3(001) and MgO(001) single crystals. Radio frequency (up to 1 MHz) and microwave (up to 50 GHz) dielectric spectroscopy studies have been carried out to characterize thin NKN films for electrically tunable microwave device applications. Films on single crystal oxide substrates showed tunabilities as high as 30-40 % at 40 V bias and dissipation factor of 0.01-0.02 at 1 MHz. The films on Si substrates showed low dielectric losses of < 0.01, and low leakage currents. Dielectric properties of ferroelectric films on Si substrates at low frequencies are greatly influenced by the depletion capacitance and the resistance inserted by semiconductor substrate. Microwave frequency measurements for NKN film on Si wafers yield more than 10 % tunability at 50 GHz and loss tan σ <0.1 at 10 GHz.

Correlation of Microwave Dielectric Properties and Microstructure of Unpatterned Ferroelectric Thin Films

2002 ◽  
Vol 720 ◽  
Author(s):  
R. G. Geyer ◽  
M.W. Cole ◽  
P.C. Joshi ◽  
E. Ngo ◽  
C. Hubbard ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Solution Deposition ◽  
Si Substrates ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Metal Insulator Metal ◽  
Resonator System ◽  
Film Substrate

AbstractThe influence of low concentration (1 mol%) Mg doping on the structural, microstructural, surface morphological and dielectric properties of Ba1-xSrxTiO3 thin films has been measured and analyzed. The films were fabricated on MgO and Pt-Si substrates via the metalorganic solution deposition technique using carboxylate-alkoxide precursors and post deposition annealed at 800 °C (film/MgO substrates) and 750 °C (film/Pt-Si substrates). The structure, microstructure, surface morphology and film/substrate compositional quality were analyzed and correlated to the films dielectric and insulating properties. Dielectric properties of unpatterned films were measured at 10 GHz with a coupled/split dielectric resonator system and at 100 kHz using metal-insulator-metal capacitors. The Mg-doped BST films exhibited improved dielectric loss and insulating characteristics compared to the undoped Ba0.6Sr0.4TiO3 thin films. The improved dielectric properties, low leakage current, and good tunability of the low level Mgdoped BST thin films merit strong potential for utilization in microwave tunable devices.

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